title: Curtatoxins. Neurotoxic insecticidal polypeptides isolated from the funnel-web spider Hololena curta.
abstract: Three polypeptide neurotoxins (curtatoxins) were isolated from the venom of the spider Hololena curta by reverse-phase high performance liquid chromatography, gel permeation, and ion-exchange chromatography. The purified toxins induced an immediate paralysis in the cricket Acheta domestica that resulted in desiccation and death of the insect within 24-48 h (LD50 congruent to 4-20 micrograms/g); this toxic effect is consistent with irreversible presynaptic neuromuscular blockade. Curtatoxins are a class of sequence-related, cysteine-rich, carboxyl-terminal amidated polypeptides of 36 to 38 amino acid residues. The cysteine residues are conserved at identical sequence positions among these polypeptides and form 4 intramolecular disulfide bonds. Hydropathy calculations show that the toxins have an internal hydrophobic region flanked by hydrophilic and oppositely charged amino- and carboxyl-terminal ends. By analogy to other cysteine-rich arthropod venom proteins, the folded structure of the curtatoxins is likely important for their target specificity and mode of action at the neuromuscular junction.
authors.affiliation: Merrell Dow Research Institute, Cincinnati, Ohio 45215.
authors.forename: A
authors.initials: A
authors.lastname: Stapleton
authors.forename: D T
authors.initials: DT
authors.lastname: Blankenship
authors.forename: B L
authors.initials: BL
authors.lastname: Ackermann
authors.forename: T M
authors.initials: TM
authors.lastname: Chen
authors.forename: G W
authors.initials: GW
authors.lastname: Gorder
authors.forename: G D
authors.initials: GD
authors.lastname: Manley
authors.forename: M G
authors.initials: MG
authors.lastname: Palfreyman
authors.forename: J E
authors.initials: JE
authors.lastname: Coutant
authors.forename: A D
authors.initials: AD
authors.lastname: Cardin
mesh_terms: D060848:Agatoxins; D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006135:Gryllidae; D007928:Lethal Dose 50; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000302:isolation & purification* / Q000633:toxicity; D009498:Neurotoxins / Q000302:isolation & purification*; D011487:Protein Conformation; D013112:Spiders; D013329:Structure-Activity Relationship
chemical_list: D060848:Agatoxins; D009479:Neuropeptides; D009498:Neurotoxins; C062739:Mu-agatoxin-Hc1b; C062738:curtatoxin I; C062740:curtatoxin III